and IntroductionAfter having successfully implemented Lean in Tenneco's Clean Air division, Tenneco Europe decided to expand Lean to its other divisions - Ride Performance including Aftermarket in 2011. These divisions were able to fully benefit from the best practices developed over the last 10 years.The implementation was articulated around two major axes: the execution of complex projects related to processes including several functions and sites. This approach allowed us to reach a critical mass in a reasonable time within the different functions and sites;the execution of smaller projects focused on one specific function,e.g.: Engineering or Sales. This approach is complementary to the first one since it enhances the spread of the lean spirit within the organization.This paper focuses on Tenneco's Ride Performance division and is split into two parts.Part 1 explains: the different steps required to implement the lean mindset;the challenges to implement it, i.e: the continuous improvement cycle, the enabling bureaucracy, the way of spreading the lean within an organization, the balance of top down and bottom up, the methodologies and ways of converting the benefits into concrete results. Part 2 illustrates: the two types of lean projects, i.e: the cross functional, multi-site ones and the small, so-called change agent projects that are more specific to a team or department. The first group of projects includes an example of the complex processes to prepare, build, pack and invoice a prototype. This involves all the key functions of an organization. The different steps of the workshop are shown.For the second group of projects (small projects) an overview shows the benefits in terms of: the just-in-time information. Some standardized planning processes and tools were developed and validated to allow the engineering community to access and utilize testing resources anywhere in the world. These measures strengthen testing flexibility by sharing resources and prevent the testing facilities suffering from over- or under-workload;Built-in-quality. The standardizations of testing procedures, engineering skills, data bases, or labeling of prototype parts are some typical examples which lead to a drastic reduction in waste, like waiting, re-work, over-processing, inventory, movement and transport;Operational stability. Better alignment between engineering departments and the improvement of some key tools like Computer Aided Design (CAD) are critical factors to improve operational efficiency. An example illustrates how a change agent project is treated.Finally, three years of lean implementation are reviewed. The outcome is very encouraging: Significant reduction of the process lead times of 20% to 50%;Freed-up time (less effort) due to the elimination of waste;Redeployment of the freed-up time for high value added tasks;Improved quality, accuracy of reporting and higher operational efficiency. ‘Soft-side’ improvements have been met such as: Improved communication and alignment between departments;Better understanding of the contribution their work makes to the overall value stream;Improved cross-functional team building through activities during Lean training and workshops;More consistent problem-solving mindset (seeing waste, finding root causes, continuous improvement);Significant improvements in motivation and morale.